Devices and methods for maintaining collateral channels in tissue

ABSTRACT

The devices and methods of placement of such devices disclosed herein are directed to altering gaseous flow within a lung to improve the expiration cycle of, for instance, an individual having Chronic Obstructive Pulmonary Disease. More particularly, these devices produce and maintain collateral openings or channels through the airway wall so that oxygen depleted/carbon dioxide rich air is able to pass directly out of the lung tissue to facilitate both the exchange of oxygen ultimately into the blood and/or to decompress hyper-inflated lungs. The medical kits disclosed herein are also directed to produce and maintain collateral openings through airway walls.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional PatentApplication Serial No. 60/269,130 filed on Feb. 14, 2001, which isincorporated herein by reference in its entirety.

FIELD OF THE INVENTION

[0002] The invention is directed to devices and methods of placing suchdevices to altering gaseous flow within a lung to improve the expirationcycle of an individual, particularly individuals having ChronicObstructive Pulmonary Disease (COPD). More particularly, methods anddevices are disclosed to produce and to maintain collateral openings orchannels through the airway wall so that oxygen depleted/carbon dioxiderich air is able to pass directly out of the lung tissue to facilitateboth the exchange of oxygen ultimately into the blood and/or todecompress hyper-inflated lungs. The invention is also directed tomedical kits disclosed which produce and maintain collateral openingsthrough airway walls.

BACKGROUND OF THE INVENTION

[0003] The term “Chronic Obstructive Pulmonary Disease” (COPD) isgenerally used to describe the disorders of emphysema and chronicbronchitis. Previously, COPD was also known as Chronic Obstructive LungDisease (COLD), Chronic Airflow Obstruction (CAO), or Chronic AirflowLimitation (CAL). Some also consider certain types of asthma to fallunder the definition of COPD. Emphysema is characterized by anenlargement of air spaces inside the lung. Hence, emphysema is ananatomic definition and it can only be presumed in a living patient.Chronic bronchitis is characterized by excessive mucus production in thebronchial tree. Chronic bronchitis is a clinical definition and denotesthose individuals who meet criteria defining the disease. It is notuncommon for an individual to suffer from both disorders.

[0004] In 1995, the American Lung Association (ALA) estimated thatbetween 15-16 million Americans suffered from COPD. The ALA estimatedthat COPD was the fourth-ranking cause of death in the U.S. The ALAestimates that the rates of emphysema is 7.6 per thousand population,and the rate for chronic bronchitis is 55.7 per thousand population.

[0005] Those inflicted with COPD face disabilities due to the limitedpulmonary functions. Usually, individuals afflicted by COPD also faceloss in muscle strength and an inability to perform common dailyactivities. Often, those patients desiring treatment for COPD seek aphysician at a point where the disease is advanced. Since the damage tothe lungs is irreversible, there is little hope of recovery. Most times,the physician cannot reverse the effects of the disease but can onlyoffer treatment and advice to halt the progression of the disease.

[0006] To understand the detrimental effects of COPD, the workings ofthe lungs requires a cursory discussion. The primary function of thelungs is to permit the exchange of two gasses by removing carbon dioxidefrom venous blood and replacing it with oxygen. Thus, to facilitate thisexchange, the lungs provide a blood gas interface. The oxygen and carbondioxide move between the gas (air) and blood by diffusion. Thisdiffusion is possible since the blood is delivered to one side of theblood-gas interface via small blood vessels (capillaries). Thecapillaries are wrapped around numerous air sacs called alveoli whichfunction as the blood-gas interface. A typical human lung contains about300 million alveoli.

[0007] The air is brought to the other side of this blood-gas interfaceby a natural respiratory airway, hereafter referred to as a naturalairway or airway, consisting of branching tubes which become narrower,shorter, and more numerous as they penetrate deeper into the lung.Specifically, the airway begins with the trachea which branches into theleft and right bronchi which divide into lobar, then segmental bronchi.Ultimately, the branching continues down to the terminal bronchioleswhich lead to the alveoli. Plates of cartilage may be found as part ofthe walls throughout most of the airway from the trachea to the bronchi.The cartilage plates become less prevalent as the airways branch.Eventually, in the last generations of the bronchi, the cartilage platesare found only at the branching points. The bronchi and bronchioles maybe distinguished as the bronchi lie proximal to the last plate ofcartilage found along the airway, while the bronchiole lies distal tothe last plate of cartilage. The bronchioles are the smallest airwaysthat do not contain alveoli. The function of the bronchi and bronchiolesis to provide conducting air ways that lead inspired air to thegas-blood interface. However, these conducting airways do not take partin gas exchange because they do not contain alveoli. Rather, the gasexchange takes place in the alveoli which are found in the distal mostend of the airways.

[0008] The mechanics of breathing include the lungs, the rib cage, thediaphragm and abdominal wall. During inspiration, inspiratory musclescontract increasing the volume of the chest cavity. As a result of theexpansion of the chest cavity, the pleural pressure, the pressure withinthe chest cavity, becomes sub-atmospheric with respect to the pressureat the airway openings. Consequently, air flows into the lungs causingthe lungs to expand. During unforced expiration, the expiratory musclesrelax and the lungs begin to recoil and reduce in size. The lungs recoilbecause they contain elastic fibers that allow for expansion, as thelungs inflate, and relaxation, as the lungs deflate, with each breath.This characteristic is called elastic recoil. The recoil of the lungscauses alveolar pressure to exceed the pressure at airway openingscausing air to flow out of the lungs and deflate the lungs. If thelungs'ability to recoil is damaged, the lungs cannot contract and reducein size from their inflated state. As a result, the lungs cannotevacuate all of the inspired air.

[0009] Emphysema is characterized by irreversible damage to the alveolarwalls. The air spaces distal to the terminal bronchiole become enlargedwith destruction of their walls which deteriorate due to a bio-chemicalbreakdown. As discussed above, the lung is elastic, primarily due toelastic fibers and tissues called elastin found in the airways and airsacs. If these fibers and tissues become weak the elastic recoil abilityof the lungs decreases. The loss of elastic recoil contributes to moreair entering the air sacs than can exit preventing the lungs fromreducing in size from their inflated state. Also, the bio-chemicalbreakdown of the walls of the alveolar walls causes a loss of radialsupport for airways which results in a narrowing of the airways onexpiration.

[0010] Chronic bronchitis is characterized by excessive mucus productionin the bronchial tree. Usually there is a general increase in bulk(hypertrophy) of the large bronchi and chronic inflammatory changes inthe small airways. Excessive amounts of mucus are found in the airwaysand semisolid plugs of this mucus may occlude some small bronchi. Also,the small airways are usually narrowed and show inflammatory changes.

[0011] In COPD, a reduction in airflow arises as a result of 1) partialairway occlusion by excess secretions, 2) airway narrowing secondary tosmooth muscle contraction, bronchial wall edema and inflation of theairways, and 3) reduction in both lung elasticity and tethering forcesexerted on the airways which maintain patency of the lumen. As a resultof the COPD, the airways close prematurely at an abnormally high lungvolume. As mentioned above, in an emphysematous lung there is a decreaseof lung parenchyma as there are larger and fewer air sacs. Thus, thereis a decrease in the amount of parenchymal tissue which radiallysupports the airways. This loss of radial traction allows the airway tocollapse more easily. As lung recoil decreases and airway closure occursat higher lung volumes, the residual volume of gas in the lungincreases. Consequently, this increased residual gas volume interfereswith the ability of the lung to draw in additional fresh gas duringinspiration. As a result, a person with advanced COPD can only takeshort shallow breaths.

[0012] One aspect of an emphysematous lung is that the flow of airbetween neighboring air sacs, known as collateral ventilation, is muchmore prevalent as compared to a normal lung. Yet, while the resistanceto collateral ventilation may be decreased in an emphysematous lung thedecreased resistance does not assist the patient in breathing due to theinability of the gasses to enter and exit the lungs as a whole.

[0013] Currently, although there is no cure for COPD, treatment includesbronchodilator drugs, and lung reduction surgery. The bronchodilatordrugs relax and widen the air passages thereby reducing the residualvolume and increasing gas flow permitting more oxygen to enter thelungs. Yet, bronchodilator drugs are only effective for a short periodof time and require repeated application. Moreover, the bronchodilatordrugs are only effective in a certain percentage of the population ofthose diagnosed with COPD. In some cases, patients suffering from COPDare given supplemental oxygen to assist in breathing. Unfortunately,aside from the impracticalities of needing to maintain and transport asource of oxygen for everyday activities, the oxygen is only partiallyfunctional and does not eliminate the effects of the COPD. Moreover,patients requiring a supplemental source of oxygen are usually neverable to return to functioning without the oxygen.

[0014] Lung volume reduction surgery is a procedure which removesportions of the lung that are over-inflated. The improvement to thepatient occurs as a portion of the lung that remains has relativelybetter elastic recoil which allows for reduced airway obstruction. Thereduced lung volume also improves the efficiency of the respiratorymuscles. However, lung reduction surgery is an extremely traumaticprocedure which involves opening the chest and thoracic cavity to removea portion of the lung. As such, the procedure involves an extendedrecovery period. Hence, the long term benefits of this surgery are stillbeing evaluated. In any case, it is thought that lung reduction surgeryis sought in those cases of emphysema where only a portion of the lungis emphysematous as opposed to the case where the entire lung isemphysematous. In cases where the lung is only partially emphysematous,removal of a portion of emphysematous lung increases the cavity area inwhich the non-diseased parenchyma may expand and contract. If the entirelung were emphysematous, the parenchyma is less elastic and cannotexpand to take advantage of an increased area within the lung cavity.

[0015] Both bronchodilator drugs and lung reduction surgery fail tocapitalize on the increased collateral ventilation taking place in thediseased lung. There remains a need for a medical procedure that canalleviate some of the problems caused by COPD. There is also a need fora medical procedure that alleviates some of the problems caused by COPDirrespective of whether a portion of the lung, or the entire lung isemphysematous. The production and maintenance of collateral openingsthrough an airway wall allows oxygen depleted/carbon dioxide rich air topass directly out of the lung tissue responsible for gas exchange. Thesecollateral openings ultimately decompress hyper inflated lungs and/orfacilitate an exchange of oxygen into the blood.

SUMMARY OF THE INVENTION

[0016] This invention relates to devices and methods for alteringgaseous flow in a diseased lung. In particular, the inventive methodincludes the act of improving gaseous flow within a diseased lung by thestep of altering the gaseous flow within the lung. A variation of theinventive method includes the act of selecting a site for collateralventilation of the diseased lung and creating at least one collateralchannel at the site. The term “channel” is intended to include anopening, cut, slit, tear, puncture, or any other conceivableartificially created opening. A further aspect of the invention is tolocate a site within a portion of a natural airway of the respiratorysystem of the patient having the diseased lung. The portion of thenatural airway selected for the creation of the collateral channels maybe, for example, the bronchi, the upper lobe, the middle lobe, the lowerlobe, segmental bronchi and the bronchioles.

[0017] A variation of the invention includes selecting a site forcreating a collateral channel by visually examining areas of collateralventilation. One variation includes visually examining the lung with afiber optic line. Another example includes the use of non-invasiveimaging such as x-ray, ultrasound, Doppler, acoustic, MRI, PET computedtomography (CT) scans or other imaging. The invention further includesmethods and devices for determining the degree of collateral ventilationby forcing gas through an airway and into air sacs, reducing pressure inthe airway, and determining the reduction in diameter of the airwayresulting from the reduction in pressure. The invention further includesmethods and devices for determining the degree of collateral ventilationby forcing a volume of gas within the lung near to the airway andmeasuring pressure, flow, or the return volume of gas within the airway.The invention also includes methods and devices for occluding a sectionof the airway and determining the degree of collateral ventilationbetween the occluded section of the airway and the air sacs.

[0018] An important, but not necessarily critical, portion of theinvention is the step of avoiding blood vessels or determining thelocation of blood vessels to avoid them. It is typically important toavoid intrapulmonary blood vessels during the creation of the collateralchannels to prevent those vessels from rupturing. Thus, it is preferableto avoid intrapulmonary or bronchial blood vessels during the creationof the collateral channels. Such avoidance may be accomplished, forexample by the use of non-invasive imaging such as radiography, computedtomography (CT) imaging, ultrasound imaging, Doppler imaging, acousticaldetection of blood vessels, pulse oxymetry technology, or thermaldetection or locating. The avoidance may also be accomplished usingDoppler effect, for example transmission of a signal which travelsthrough tissue and other bodily fluids and is reflected by changes indensity that exist between different body tissue/fluids. If the signalis reflected from tissue/fluid that is moving relative to the sensor,then the reflected signal is phase shifted from the original signalthereby allowing for detection.

[0019] Another variation of the inventive device includes a device thatdetects motion within tissue using Doppler measurements. The device mayinclude a flexible member having a transducer assembly that is adaptedto generate a source signal and receive a reflected signal. Thetransducer assembly may include an acoustic lens which enables thetransmission and detection of a signal over a tip of the device.

[0020] Another variation of the invention includes marking the siteafter it is located. Accordingly, once marked, a previously selectedsite can be located without the need to re-examine the surrounding areafor collateral ventilation, or the presence or absence of a bloodvessel. The marking may be accomplished by the deposit of a remotelydetectable marker, dye, or ink. Or, the marking may comprise making aphysical mark on the surface of the airway to designate the site.Preferably, the mark is detectable by direct visualization or suchimaging methods as radiography, computer tomography (CT) imaging,ultrasound imaging, doppler imaging, acoustical detection, or thermaldetection or locating.

[0021] The invention may also include a user interface which providesfeedback once an acceptable site is located. For example, once a site islocated a visual or audible signal or image is transmitted to the userinterface to alert the user of the location of a potential site. Thesignal could be triggered once a blood vessel is located so that thesite is selected in another location. In another example, the signal maytrigger so long as a blood vessel is not located.

[0022] The invention may include adding an agent to the lungs forimproving the imaging. For example, a gas may be inserted into the lungsto provide contrast to identify hyperinflation of the lungs during anx-ray or other non-invasive imaging. For example, ¹³³Xe (Xenon 133) maybe used as the agent. Also, a contrast agent may help in identifyingblood vessels during CT scans. Another example includes inserting afluid in the lungs to couple an ultrasound sensor to the wall of anairway.

[0023] The invention may also include providing a remotely detectablesignal to indicate the presence or absence of any blood vessels at thetarget site. The invention also includes methods and devices for markinga desired site for the creation of a collateral channel.

[0024] The invention also includes the act of creating one or morecollateral channels within the respiratory system of the individual. Thecollateral channels may have a cross sectional area anywhere between0.196 mm² to 254 mm². Any subset of narrower ranges is alsocontemplated. The collateral channels may also extend anywhere fromimmediately beyond the epithelial layer of the natural airway to 10 cmor more beyond the epithelial layer. The channel or channels should becreated such that the total area of the channel(s) created is sufficientto adequately decompress a hyperinflated lung. The channel may be, forexample, in the shape of a hole, slit, skive, or cut flap. The channelmay be formed by the removal of any portion of the airway wall; e.g., acircumferential or arc-shaped ring of material may be removed to formthe channel. Such an excised periphery may be for example, perpendicularor angled with respect to the axis of the airway.

[0025] Also, it is anticipated that along with any method of creating acollateral channel any loose material or waste generated by the creationof the collateral channel is optionally removed from the airway.

[0026] Another variation for creating the collateral channel is thecreation of the airway using electric energy, for example radiofrequency. Or, for example, ultrasonic energy, a laser, microwaveenergy, chemicals, thermal, or cryo-ablative energy may be used to forma collateral channel as well. A feature of these methods often includescreation of a hemostasis in the event that any blood vessel ispunctured. For example, use of RF energy provides a hemostasis given apuncture of a vessel by using heat to seal the vessel. Similarly, anultrasonic scalpel also provides an area of hemostasis in case thevessel is punctured. It is understood that any combination of differentmethods may be used for forming a single or multiple collateralchannels. A variation of the invention includes a limiter for limitingthe depth of a collateral channel.

[0027] Another variation of the inventive device includes combining thedoppler catheter described above with a hole-making assembly that isadapted to form collateral channels within tissue. The hole-makingassembly may be an RF device and use portions of the tip of the deviceas RF electrodes, or the hole-making assembly may use ultrasound energyto make the hole. Alternatively, the hole-making assembly may be thetransducer assembly described above which may be operated at anintensity which causes the transducer assembly to function as ahole-making device.

[0028] Another variation of the invention includes the act of insertingan implant or conduit within a collateral channel to maintain thepatency of the channel over time during the expiration cycle of thelung. A conduit could, for example, have distal and proximal ends with awall defining a lumen extending between the ends. The conduit couldhave, for example, a porous wall permitting the exchange of gassesthrough the wall. The conduit may, for example, be comprised of amaterial such as elastomers, polymers, metals, metal alloys, shapememory alloys, shape memory polymers, or any combination thereof. Avariation of the invention includes an expandable conduit, either onethat is self-expanding, or one that expands in diameter in relation toany applied radial, or axial force. For example, the conduit may beexpanded into an opening of the natural airway upon the inflation of aballoon. A variation of the conduit may include the use of flanges oranchors to facilitate placement of the device within an airway. Anothervariation of the conduit includes placing a one-way valve within theconduit. Another variation includes using a self cleaning mechanismwithin the conduit to clear accumulating debris.

[0029] The invention includes the method of feeding a guidewire to asite within the lung, advancing a conduit to the site using theguidewire, and placing the conduit within the lung tissue at the site.The method may include inserting an access device, such as abronchoscope, within airways of the lung to locate a site within thelung for creation of the collateral channel. The access device couldalso be used as an access device so that the required devices may beintroduced to the site. A catheter having a conduit attached thereto maybe advanced over the guide-wire for insertion of the conduit within thecollateral channel.

[0030] The inventive conduit may be, for example, removable orpermanent. Also, another variation of the device includes a means forinserting the conduit within a collateral channel. The conduit may beconstructed to allow for passage of gasses through its wall, forexample, the conduit may have a wall consisting of a braid. A variationof the conduit may be located through an opening in a wall of an airwayand engage both an inside and outside of the wall. Another variation ofthe conduit includes a distal end having a porous member and a proximalend having a grommet member which engages an opening in a wall of thenatural airway. Yet another variation of the implant, for example,comprises an expandable conduit-like apparatus which could bridge anopening within a wall of a natural airway. Another variation includesthe conduit-like apparatus having a cutting portion exterior to thedevice wherein expansion of the device pierces the wall of the naturalairway and creates a collateral channel.

[0031] An aspect of the invention is that conduits of varyingcross-sectional areas may be placed in various sections of the lung tooptimize the effect of the collateral channels.

[0032] Another variation of the invention includes the application of acyano-acrylate, fibrin or other bio-compatible adhesive to maintain thepatency of a collateral channel. The adhesive may be used with orwithout the conduit described above. For example, the adhesive may bedeposited within the collateral channel to maintain patency of thechannel or to create a cast implant of the channel. The inventive actfurther includes the act of delivering medications such as steroidswhich have been shown to inhibit the healing process, bronchodilators,or other such drugs which aid in breathing, fighting infection, orrecovery from the procedure. The steroids inhibit inflammation and thenpromote the stabilization of the created channel.

[0033] Another variation of the inventive process includes promoting theflow of gasses through under-utilized parenchymal inter-conduits, orbypassing restricted airways. It is also contemplated that the gaseousflow may be altered by, for example, making separate inspiratory andexpiratory paths. Also, relieving pressure on the external wall of anatural airway may be accomplished to assist the natural airway bymaintaining patency during the expiration cycle of the lung. Yet anothervariation includes creating collateral channels parallel to existingairflow paths, or the existing airflow paths may be increased incross-sectional area.

[0034] The invention further includes a modified respiratory airwayhaving an artificially created channel allowing gaseous communicationbetween an exterior of the airway and an interior of the airway.

[0035] The invention may include an endoscope or a bronchoscopeconfigured to select sites and create collateral channels at thosesites. An endoscope or a bronchoscope may also be configured to deployconduits within the collateral channels. Another variation of theinvention includes sizing the device to fit within the working channelof a bronchoscope.

[0036] The invention also includes methods for evaluating an individualhaving a diseased lung for a procedure to create collateral channelswithin an airway of the individual. The invention further includes themethod of determining the effectiveness of the procedure.

[0037] The invention further includes the act of teaching or providinginstructions for any of the methods described herein or for using any ofthe devices describe herein.

[0038] The invention further includes the method of sterilizing any ofthe devices or kits described above.

BRIEF DESCRIPTION OF THE DRAWINGS

[0039]FIGS. 1A-1C illustrates various states of the natural airways andthe blood-gas interface.

[0040]FIG. 1D illustrates a schematic of a lung demonstrating aprinciple of the invention described herein.

[0041]FIGS. 2A-2C illustrate devices and methods for determining thedegree of collateral ventilation within a lung.

[0042]FIGS. 3A-3P illustrate methods of and devices for creating acollateral opening within a natural airway.

[0043]FIGS. 4A-4B illustrate a method of folding epithelial tissuethrough a collateral channel.

[0044]FIGS. 5A-5D illustrate devices for detecting blood vessels withintissue.

[0045]FIGS. 5E-5V illustrates various devices for detecting bloodvessels within tissue where the devices also include hole-makingassemblies.

[0046]FIGS. 6A-6G illustrate various electrode configurations for thehole-making assemblies of the device.

[0047]FIGS. 6H-6J illustrates additional variations of the lens of thepresent invention.

[0048]FIGS. 7A-7B illustrate devices and methods for creating acollateral channel with a device having a hole-making assembly and alsopreserving the tissue surrounding the collateral channel.

[0049]FIGS. 7C-7D illustrate additional electrode configurations for usewith a device of the present invention where the structure of theelectrodes limits the possible depth of a collateral channel formed bythe electrode.

[0050]FIGS. 8A-8V illustrate various configuration of implantableconduits.

[0051]FIGS. 9A-9U, 10A-10B, and 11A-11C illustrate variations ofconduits of the present invention.

[0052]FIGS. 12A-12I illustrate variations of methods and devices fordeployment of conduits of the present invention.

[0053]FIGS. 13A-13F illustrate methods of placing a conduit withintissue.

DETAILED DESCRIPTION OF THE INVENTION

[0054] Prior to considering the invention, simplified illustrations ofvarious states of a natural airway and a blood gas interface found at adistal end of those airways are provided in FIGS. 1A-1C. FIG. 1A shows anatural airway 100 which eventually branches to a blood gas interface102. FIG. 1B illustrates an airway 100 and blood gas interface 102 in anindividual having COPD. The obstructions 104 impair the passage of gasbetween the airways 100 and the interface 102. FIG. 1C illustrates aportion of an emphysematous lung where the blood gas interface 102expands due to the loss of the interface walls 106 which havedeteriorated due to a bio-chemical breakdown of the walls 106. Alsodepicted is a constriction 108 of the airway 100. It is generallyunderstood that there is usually a combination of the phenomena depictedin FIGS. 1A-1C. More usually, the states of the lung depicted in FIGS.1B and 1C are often found in the same lung.

[0055] The following illustrations are examples of the inventiondescribed herein. It is contemplated that combinations of aspects ofspecific embodiments or combinations of the specific embodimentsthemselves are within the scope of this disclosure.

[0056] As will be explained in greater detail below, central to thisinvention in all of its aspects is the production and maintenance ofcollateral openings or channels through the airway wall so that oxygendepleted/carbon dioxide rich air is able to pass directly out of thelung tissue and into the airways to ultimately facilitate exchange ofoxygen into the blood and/or decompress hyper inflated lungs. The term‘lung tissue’ is intended to include the tissue involved with gasexchange, including but not limited to, gas exchange membranes, alveolarwalls, parenchyma and/or other such tissue. To accomplish the exchangeof oxygen, the collateral channels allow fluid communication between anairway and lung tissue. Therefore, gaseous flow is improved within thelung by altering or redirecting the gaseous flow within the lung, orentirely within the lung. FIG. 1D illustrate a schematic of a lung 118to demonstrate a principle of the invention described herein. As shown,a collateral channel 112 places lung tissue 116 in fluid communicationwith airways 100 allowing oxygen depleted/carbon dioxide rich air todirectly pass out of the airways 100. The term channel is intended toinclude an opening, cut, slit, tear, puncture, or any other conceivableartificially created opening. As shown, constricted airways 108 mayordinarily prevent air from exiting the lung tissue 116. In the exampleillustrated in FIG. 1D, conduits 200 may be placed in the collateralchannels 112 to assist in maintaining the patency of the collateralchannels 112. Therefore, it is not necessary to pierce the pleura toimprove gaseous flow within the lungs. While the invention is notlimited to the number of collateral channels which may be created, it ispreferable that 1 or 2 channels are placed per lobe of the lung. Forexample, the preferred number of channels is 2-12 channels perindividual patient.

[0057] Accordingly, since the invention is used to improve the functionof the lungs, a variation of the inventive device may include anendoscope or a bronchoscope configured to locate a site for creating acollateral channel and create the collateral channel. Another variationincludes sizing the inventive device to fit within a working channel ofan endoscope or a bronchoscope. For the sake of brevity, hereafter, anyreference made to an endoscope includes the term bronchoscope.

[0058] The invention includes assessing the degree of the collateralventilation taking place in an area of a lung to select a site forcreation of a collateral channel. The invention may include locating asite for creation of a collateral channel by visually examining anairway for dynamic collapse. One method of visual examination includesthe use of a fiber optic line or camera which may be advanced into thelungs and through the airways. Other variations of visually examiningthe lung to determine the location of a site for the creation of thecollateral channel using non-invasive imaging, including but not limitedto radiography, computer tomography, ultrasound, Doppler, and acousticimaging. Such imaging methods may also be used to determine the amountof collateral channels to be created.

[0059] Also contemplated in the invention is the addition of variousagents to assist during imaging of the airways or lungs. One exampleincludes the use of a non-harmful gas, such as Xenon, to enhance thevisibility of hyperinflated portions of the lung during radiologicalimaging. Another example includes the use of inserting a fluid in thelungs to provide an improved sound transmission medium between thedevice and the tissue in variations of the invention using ultrasound,acoustic, or other imaging.

[0060] Another variation of the invention includes methods and devicesfor triggering a collapse of the airway to determine the degree ofcollateral ventilation in the lung. One example includes forcing afluid, such as a gas, air, oxygen, etc., through the airway and into theair sacs. Next, to assess the patency of the airway, the pressure isreduced in the airway. One example of how pressure is reduced in theairway includes evacuating the air in a direction opposite to the airsacs. Constriction of the airway given a drop in pressure may be anindication of collateral ventilation of the lung in that region.

[0061]FIG. 2A, illustrates a method and device 212 for causing collapseof the airway wall 100. The device 212 includes a fluid delivery member214 located at a distal end of the device 212. The fluid delivery member214 is configured to deliver a volume of fluid through the airway 100and into an air sac (not shown). The device 212 may also comprise aprobe 216 configured to collect data within the lung. The probe 216 mayalso simply consist of a channel that transmits signals outside of thelung. Moreover, the fluid delivery member 214 and the probe 216 may notbe separate channels. Also, the device 212 may, but does notnecessarily, have an occlusion member 218 designed to isolate a sectionof the airway 100 between the occlusion member 218 and the air sacs (notshown). The occlusion member 218, which forms a seal against the airway100 walls, may provide a partially closed system allowing a moreeffective search for collateral ventilation between the air sacs (notshown.) The device delivers a burst of fluid, through the fluid deliverymember 214 and subsequently uses the probe 216 to measurecharacteristics such as pressure, flow, or return volume to determinethe degree of collateral ventilation. The term fluid is intended toinclude, air or a gas, such as oxygen, etc. For example, if the air sacsare diseased (as shown in FIG. 1C), the forced fluid willescape/disperse through another air sac due to the collateralventilation of the air sacs. As a result, the probe 216 may fail torecord any increase in pressure, volume, flow, or any othercharacteristic of the fluid at the site. Another variation of theinvention includes using the fluid delivery member 214 to add or removefluid distally to the occluded segment and using the probe 216 tomonitor flow or pressure changes in the area. For example, if afteradding/removing fluid the pressure in the occluded segment fails tobuild/drop, the assumption may be made that the gas is beingcollaterally vented through diseased air sacs.

[0062]FIG. 2B illustrates another variation of the invention. In thisexample, the device 220 comprises a separated probe 216 and gas deliverymember 214. In this variation, the fluid delivery member 214 isconfigured to pass through a wall of the airway 100 so that fluid may bedirectly forced into, or pulled out of an air sac 102.

[0063]FIG. 2C illustrates yet another variation of the invention. Inthis variation, the device 222 may have at least one fluid exchangepassageway 224. The device 222 may force fluid into the airway 100 viathe passageway 224. Then, fluid can be pulled out via the passageway224, thus decreasing pressure distally to the device 222. The decreasein pressure permits fluid to flow out of the airway 100 and away fromthe air sac (not shown). In this case, if the air sacs surrounding theairway 100 are diseased and collateral ventilation is taking place, thenthe airway 100 may collapse. A variation of the invention may include anexpandable member 218, such as a balloon, to create a seal against theairway 100 walls. Forming a seal may provide a partially closed systemto search for collateral ventilation between air sacs (not shown.) Asdescribed above, observation of a collapsing airway 100 may indicate adesired site for creation of a collateral channel.

[0064]FIGS. 3A-3I depict various ways of providing openings in theairway wall which may be used as collateral air passageways.

[0065]FIG. 3A illustrates an airway 100 having a piercing member 300 anda dilation member 302. In this example, the piercing member 300 makes anincision (not shown) in the airway 100 wall. Next, the piercing member300 is advanced into the wall so that a dilation member 302 can expandthe incision to thereby provide a collateral channel. In this example,the dilation member 302 is depicted as a balloon. One variation of theinvention includes filling a balloon with a heated fluid as the balloondilates the tissue to form the collateral channel. Use of a heatedballoon allows the transfer of heat to the collateral channel formodifying the healing response. However, it is also contemplated thatthe dilation member may be an expanding wedge (not shown) or othersimilar device.

[0066]FIG. 3B shows a cutting device 304 and an airway 100 having anopening 306 cut from a wall. In this example, a flap 308 is cut from thewall and is attached to an outside or an inside wall of the airway 100.As will be mentioned below, the flap may be glued, using for instance,fibrin-based or cyano-acrylate-based glues or stapled to that wall.

[0067]FIG. 3C illustrates a cutter 304 making an incision 310 in a wallof the airway 100. FIG. 3D illustrates one example of placing the wallsof the airway 100 in tension and inserting a blunt instrument 314 intothe incision. In this example, the delivery device 312 is flexible andmay be shaped to the contour of an airway 100 to provide support for theblunt instrument 314 so that the instrument 314 can advance into theincision. The delivery device 312 is also used to deliver a bluntinstrument 314 which expands the original incision. The blunt instrument314 may have a hooked configuration as needed.

[0068]FIG. 3E shows the use of a balloon 320 to dilate a previouslyformed collateral channel in the airway wall 100. This procedure may beused variously with other mechanical, chemical, cryo-energy, thermal orRF based penetration systems to expand the size of thatpreviously-formed opening. It should be noted, that variations of theinventive device described herein using energy to create a collateralchannel will require a power supply to be coupled to the active heatingelement. For sake of convenience, the power supply is not alwaysillustrated in the Figures.

[0069]FIG. 3F illustrates a variation of the device 322 having an RFelectrode 324. This variation of the invention uses RF energy to createa collateral channel. The device 322 may be mono-polar or bi-polar. TheRF energy throughout this invention is similar to that of a typical RFcutting probe operating between the 300 KHz-600 KHz range. FIGS. 3G-31illustrates additional variations of devices of the present inventionused to create collateral channels. The devices may use RF energy,either monopolar or bipolar, or the devices may use light, infraredheat, or any of the other methods describe herein. In the variation ofFIG. 3G, the device 328 has an electrode 324 located on a side of thedevice. This variation of the device 328 automatically limits the depthof the collateral channel as the body of the device 328 remains againstan airway 100 wall while the electrode 324 creates a channel.

[0070]FIGS. 3H and 3I illustrates another variation of a device 330 ofthe present invention having an electrode 324 located on a front face ofthe device. FIG. 3I illustrates a perspective view of the device 330with an electrode on the front face 324. The device 330 may either havean electrode 324 disposed on a front surface of the device 330 or thedevice may comprise a conductive material with an insulating layer 332covering the device 330 and leaving an electrode surface 324 exposed. Inthe variations illustrated in FIGS. 3G-31, the size of the electrode maybe selected based upon the size of the desired collateral channel.

[0071] The device of the present invention may also be configured tolimit the depth of the collateral channel. In one example, FIG. 3F, theinvention may include a shoulder or stop 326 to limit the depth of thecollateral channel. Another example includes graduated index markings ona proximal end of the device or on the distal end so long as they areremotely detectable. Also contemplated is the use of RF impedancemeasuring. In this example, the use of RF impedance may be used todetermine when the device leaves the wall of the airway and enters theair sac or less dense lung tissue.

[0072]FIG. 3J illustrates another variation of a device 334 of thepresent invention adapted to create collateral channels. In thisvariation, the device 334 includes an elongate body 336 which may have alumen extending therethrough. The device 334 further includes a heatingelement 338 extending from the elongate body 336. The heating elementdescribed herein for the variations of the invention may be the typewhich actually generates heat in the element, such as, for example, aresistive heating element. Furthermore, the heating element describedherein for the variations of the invention may be the type whichactually generates heat directly within the tissue, for example, an RFelectrode. In any case, the heating element of the present inventionshall have a heating surface located on the front surface of the heatingelement that is adapted to minimize heat in a radial direction from theheating element. Accordingly, the heating element will preferably be acone, hemispherical, or similar member that is shallow in depth. In onevariation, the heating surface will have a depth (as illustrated bydepth 341 in FIG. 3J) which is less than the diameter of the heatingsurface. For example, the depth could be less than the radius of theheating surface. As a result of this configuration, heat generated bythe heating element is directed towards creating channels or holes.Minimizing heat in a radial direction from the heating element preventsexcessive heating of the walls of the collateral channel or hole withinthe tissue.

[0073] The heating element 338 shown in FIG. 3J includes a heatingsurface 340 which is located over the front surface of the heatingelement 338. The heating element 334 may be any type of heat generatingdevice described herein and is coupled to its respective power supply.In one variation, the heating element 338 comprises an RF electrode. Insuch a case, the heating element 338 is coupled to an RF generator (notshown). Although not illustrated, a variation of the device includes aheating element which extends through the lumen of the elongate member.The heating element may extend throughout the elongate member or it mayextend partially into the elongate member.

[0074] The variation of the devices described herein may also includeinsulating surfaces. For example, in FIG. 3J, the device 334 may have atleast one insulating surface 342 located adjacent to the heating surface340. The insulating surface 342 shields tissue from heat generated bythe heating element 338 as the heating element 338 creates a collateralchannel in tissue. The insulating surfaces described herein may beconfigured to shield tissue from heat generated by the heating element,or, the insulating surface may prevent heat from being generated in thetissue which is adjacent to the insulating surface (e.g., in an RFhole-making device). Each of these materials is selected to havesufficient properties (e.g., low thermal conductivity, non-conductive,etc.). An insulating surface may comprise a ceramic material, such asalumina oxide, zirconia oxide, silicon nitride, silicate, etc. Theinsulating surface may also comprise a plastic tubing such as Nylon,polyimide, PTFE, Pebax, etc. Other examples include insulating surfacescomprising, for example, an epoxy, or a bio-compatible coating such asparalene. Alternatively, the insulating surface may comprise acombination of the above listed materials. As discussed above, it isnoted, that the device may be used without an insulating surface 342.

[0075] The device 334 may further include a shoulder 344 located on theelongate body 336 and proximate to the heating element 338. The shoulder344 is configured to expand to a diameter greater than a diameter of theelongate body 336. Accordingly, the shoulder 334 serves as a stop ordepth limiter for the device 334 as it creates a collateral channel. Inthe variation illustrated in FIG. 3J, the shoulder 344 comprises aballoon, which has a reduced profile (illustrated) and an expandedprofile. FIG. 3K illustrates the balloon 344 in the expanded profile.The maximum diameter of a shoulder used in any variation of theinvention described herein may vary depending upon the application.Currently, it is believed that a shoulder should be greater than 3 mm indiameter. The balloon may be constructed from silicone, urethane, orother such materials. The elongate member of the variations describeherein may be comprised of a nylon, polyethylene, polycarbonate, etc.,or a combination thereof.

[0076] It is noted that a variation of the device of the presentinvention may have a shoulder 344 comprised of other than a balloon, butis simply a structure which has a diameter greater than a diameter of aheating element on the device. In such a case, referring to theillustration of FIG. 3K, the shoulder 344 would not be adjustable in aradial direction from the elongate member 336.

[0077]FIG. 3L illustrates another variation of a device 346 of thepresent invention adapted to create collateral channels. In thisvariation, the device 346 includes an elongate body 348 which may have alumen extending therethrough. The device 346 further includes a heatingelement 338 extending from the elongate body 348. Wherein the heatingelement 338 includes a heating surface 340 which may be located over thefront surface of the heating element 338. As described above, theheating element 338 may be any type of heat generating device describedherein and is coupled to its respective power supply. In one variation,the heating element 338 comprises an RF electrode. In such a case, theheating element 338 is coupled to an RF generator (not shown).

[0078] The variation of the device 346 illustrated in FIG. 3L may alsoincludes an insulating surface 342 located adjacent to the heatingsurface 340. The insulating surface 342 shields tissue from heatgenerated by the heating element 338 as the heating element 338 createsa collateral channel in tissue.

[0079] The device 346 of FIG. 3L further includes a shoulder 350 locatedon the elongate body 348 and proximate to the heating element 338. Asdescribed above, the shoulder 350 is configured to expand to a diametergreater than a diameter of the elongate body 348 allowing the shoulder350 to serve as a stop or depth limiter for the device 346 as it createsa collateral channel. In the variations illustrated in FIGS. 3L and 3M,the shoulder 350 is comprised of a plurality of hinged members 352 eachof which is adapted to expand in diameter from the expandable member348. In this variation, the hinged members 352 each have a living hinge354 which allows the hinged members 352 to assume an expanded or reducedprofile. In the variation depicted in FIGS. 3L and 3M, the hingedmembers 352 expand away from the elongate member 348 given relativemovement between the elongate member 348 and the heating element 338.For example, as illustrated in FIG. 3M, the heating element 338 may bepulled in a proximal direction against the elongate member 348 causingthe insulating surface 342 to force the hinged members 352 outwardly. Asa result, the shoulder 350 assumes an expanded profile. Although thehinged members 352 are illustrated as being parallel to the lumen of theelongate member 348, the invention is not limited as such. Moreover, thenumber of hinged members 352 is not limited to that which isillustrated. It is contemplated that variations of the inventive devicemay include 2 or more hinged members.

[0080] In the devices illustrated in FIGS. 3J-3M, although the heatingelement is depicted as being spaced from the elongate member, theinvention is not limited as such. For example, in variations where theheating element is not slidably located in the elongate member, a devicemay have a gap between the heating element and the elongate member suchthat the insulating surface is against or within the elongate member.Moreover, the device may be designed to have a pre-determined gapbetween the insulating surface and the elongate member. Alternatively,for any of the variations described herein, there may be no gap betweenthe insulating surface and the elongate member.

[0081]FIGS. 3N-3P illustrate another variation of the inventive devicewhich is adapted to create collateral channels. In this variation, theheating element 338 is moveably located within an elongate member 360.At least a portion of the lumen of the elongate member 360 has a reducedopening 362 which is smaller than a diameter of the heating element 338.As shown in FIG. 3P, a distal end of the elongate member 360 may beradially adjustable to permit the heating element 360 to move in and outof the lumen. In the variation of the device depicted in FIG. 3P, thefront surface of the elongated member 360 functions as a shoulder 364when the heating element 338 extends from the front of the elongatedmember 360. The distal end of the elongated member 360 may be remotelyactuated to expand, or, the distal end may be biased to expandoutwardly. In the latter case, the distal end may be restrained, forexample, by an outer tubular member 366. The outer tubular member 336may also be used to reduce the diameter of the distal end to closeagainst the heating element 338, as shown in FIG. 3P. The distal end ofthe elongated member 360 may be a continuous tubular structure whichexpands in diameter, or it may be a tubular structure that divided intoany number of portions which permit the radial expansion of the distalend. For example, FIG. 3N illustrates a front view of the device of FIG.30 in which at least a segment of the elongated member 360 is dividedinto four portions 368 so that it may be radially adjustable. It isunderstood that the number of portions 368 illustrated are merelyexemplary, as the number may be varied as needed. Furthermore, theelongated member 360 may not be divided into any such portions 368 andinstead may be an expandable elastic member comprised of, for example:silicone, urethane, etc.

[0082] The invention also includes creating a collateral channel bymaking a single or a series of incisions in an airway wall then foldingback the cut tissue through the collateral channel. This procedureallows the surface epithelium which was previously on the inside of theairway wall to cover the walls of the newly formed collateral channel.As discussed herein, promoting growth of the epithelium over the wallsof the collateral channel provides a beneficial healing response. Theincision may be created by the use of heat or a mechanical surface. Forexample, FIG. 4A illustrates a section of an airway 100 having severalincisions 356 forming a number of sections 358 of airway wall tissue theairway 100. FIG. 4B illustrates the sections or flaps 358 of the airwaywall folded through the collateral channel 112. Any number of incisions358 may be made to form any number of sections 358 of airway wall tissueas desired. For example, a plus-shaped incision would result in foursections of tissue that may be folded through a channel. The sections358 may be affixed with a suture material, an adhesive, or the sections358 may simply be inserted into surrounding tissue to remain foldedthrough the collateral channel 112.

[0083] Another variation of the device includes safety features such asprobes to determine the presence of blood. If a probe indicates that ablood vessel is contacted or penetrated, a signal is sent which preventsthe channel making device from causing further harm to the vessel. Sucha feature minimizes the risk of inadvertently puncturing a blood vesselwithin the lungs.

[0084] Although the examples depict mechanically forming a collateralopening, the invention is not limited to such. Alternative methods offorming the opening are contemplated in the use of RF energy, bi-polar,or single pole electrosurgical cutters, ultrasonic energy, laser,microwave, cryo-energy, thermal, or chemicals.

[0085] Another variation of the invention includes methods and devicesfor determining whether a blood vessel is in proximity to a potentialsite. Making this determination prior to creating the channel isadvantageous as the risk of puncturing a blood vessel is minimized. Itis important that the devices of the present invention do not ‘wander’resulting in the creation of a collateral channel at a distance from thearea originally searched. Such an occurrence may compromise a bloodvessel (e.g., puncture, rupture, or otherwise open the blood vessel)even though the step of detecting the location indicated the absence ofa blood vessel. In those cases, a device having a stiffer wall providesadded benefits. Accordingly, the devices must be flexible to navigate toa target site, yet once they reach the target site the device should beconfigured to minimize subsequent movement.

[0086] The present invention includes the use of a device which is ableto detect the presence or absence of a blood vessel by placing a frontportion of the device in contact with tissue. One variation of theinvention includes the use of Doppler ultrasound to detect the presenceof blood vessels within tissue. It is known that sound waves atultrasonic frequencies travel through tissue and reflect off of objectswhere density gradients exist. In which case the reflected signal andthe transmitted signal will have the same frequency. Alternatively, inthe case where the signal is reflected from the blood cells movingthrough a blood vessel, the reflected signal will have a shift infrequency from the transmitted signal. This shift is known as a Dopplershift. Furthermore, the frequency of the signals may be changed fromultrasonic to a frequency that is detectable within the range of humanhearing.

[0087] The ultrasound Doppler operates at any frequency in theultrasound range but preferably between 2 Mhz-30 Mhz. It is generallyknown that higher frequencies provide better resolution while lowerfrequencies offer better penetration of tissue. In the presentinvention, because location of blood vessels does not require actualimaging, there may be a balance obtained between the need for resolutionand for penetration of tissue. Accordingly, an intermediate frequencymay be used (e.g., around 8 Mhz). A variation of the invention mayinclude inserting a fluid into the airway to provide a medium for theDoppler sensors to couple to the wall of the airway to detect bloodvessels. In those cases where fluid is not inserted, the device may usemucus found within the airway to directly couple the sensor to the wallof the airway.

[0088]FIG. 5A illustrates a variation of a device 600 adapted todetermine the presence of blood vessels as previously mentioned. Thedevice 600 includes a flexible elongate member 604 having a transducerassembly 606, at least a portion of which is located adjacent to adistal end of the elongate member 604. Although the elongate member 604is illustrated as having a lumen, the elongate member 604 may also beselected to be solid, or the elongate member 604 may have a supportmember (not shown) such as a braid to increase the strength and/ormaneuverability of the device. The transducer assembly 606 is adapted togenerate a source signal and receive a reflected signal. It may use asingle transducer or multiple transducers. For example, at least a firsttransducer may be used to generate a signal and at least a secondtransducer may be used to receive the signal.

[0089] The transducer or transducers may comprise a piezo-ceramiccrystal. In the current invention, a single-crystal piezo (SCP) ispreferred, but the invention does not exclude the use of other types offerroelectric material such as poly-crystalline ceramic piezos, polymerpiezos, or polymer composites. The substrate, typically made frompiezoelectric single crystals (SCP) or ceramics such as PZT, PLZT, PMN,PMN-PT; also, the crystal may be a multi layer composite of a ceramicpiezoelectric material. Piezoelectric polymers such as PVDF may also beused. The transducer or transducers used may be ceramic pieces coatedwith a conductive coating, such as gold. Other conductive coatingsinclude sputtered metal, metals, or alloys, such as a member of thePlatinum Group of the Periodic Table (Ru, Rh, Pd, Re, Os, Ir, and Pt) orgold. Titanium (Ti) is also especially suitable. For example, thetransducer may be further coated with a biocompatible layer such asParylene or Parylene C. The transducer is then bonded on the lens. Acoupling such as a biocompatible epoxy may be used to bond thetransducer to the lens. The transducer assembly 606 communicates with ananalyzing device 602 adapted to recognize the reflected signal ormeasure the Doppler shift between the signals. As mentioned above, thesource signal may be reflected by changes in density between tissue. Insuch a case, the reflected signal will have the same frequency as thetransmitted signal. When the source signal is reflected from bloodmoving within the vessel, the reflected signal has a different frequencythan that of the source signal. This Doppler effect permitsdetermination of the presence or absence of a blood vessel withintissue. Although depicted as being external to the device 600, it iscontemplated that the analyzing device 602 may alternatively beincorporated into the device 600. The transducer assembly of theinvention is intended to include any transducer assembly that allows forthe observation of Doppler effect, e.g., ultrasound, light, sound etc.The device 600 illustrated in FIG. 5A includes a transducer assembly 606comprising an ultrasound transducer 608 and an acoustic lens 610 that isadapted to refract and disperse a source signal over an outer surface ofthe lens 610. The lens 610 is designed such that it interferes andredirects the signals in a desired direction. The lens 610 may becomprised of materials such as dimethyl pentene (plastic-TPX), aluminum,carbon aerogel, polycarbonate (e.g., lexan), polystyrene, titanium, etc.It also may be desirable to place an epoxy between the lens 610 and thetransducer 608. Preferably, the epoxy is thin and applied without airgaps or pockets. Also, the density/hardness of the epoxy should providefor transmission of the signal while minimizing any effect or change tothe source signal. The configuration of the transducer assembly 606permits the lens 610 to disperse a signal over a substantial portion ofthe outer surface of the lens 610. The lens 610 also is adapted torefract a reflected signal towards the transducer 608. Accordingly,given the above described configuration, the device 600 of FIG. 5A willbe able to detect vessels with any part of the lens 610 that contactstissue (as illustrated by the line 612-612.) Although the lens 610 isillustrated as being hemispherical, as described below, the lens 610 mayhave other shapes as well.

[0090]FIG. 5B illustrates another variation of the device 614 having ahemispherical shaped ultrasound transducer 618 affixed to an end of aflexible elongate member 616. The transducer 618 communicates with ananalyzing device (not shown) to measure the Doppler effect to determinethe location of a blood vessel.

[0091]FIG. 5C illustrates another variation of the device 620 includinga transducer assembly 622, at least a portion of which is locatedadjacent to a distal end of the elongate member 628. The transducerassembly 622 includes a flat ultrasound transducer 626, and a cone orwedge-like acoustic mirror 624. The mirror 624 is adapted to reflect thesignal over an area 360° around the device. The angle α of the mirrormay be varied to optimally direct the signal as needed.

[0092]FIG. 5D illustrates a variation of a device 630 of the presentinvention further comprising a joint 632 to articulate an end of thedevice either to make sufficient contact with an area of tissue to beinspected for the presence of a blood vessel, or to navigate within thebody to access the area to be inspected.

[0093] The variations of the invention described herein may also beadapted to use ultrasound energy, for example, high energy ultrasound,to produce openings in or marks on tissue. In such a case, thetransducer assembly and acoustic lens also functions as a hole-making orsite marking device. In this case, use of ultrasound in a low poweroperation permits the detection of a blood vessel and location of a sitefor a collateral channel. Using the same device and switching theoperation of the device to a high power ultrasound permits the use ofthe ultrasound to create a collateral channel.

[0094]FIG. 5E illustrates a variation of a device 632 comprising atransducer assembly 634 connected to a flexible elongate member 636. Inthis example, the transducer assembly 634 comprises a first transducer641, a second transducer 642, and an acoustic lens 640. As mentionedabove, in variations using alternate transducers 641, 642, onetransducer may transmit a signal while the other receives a signal.Also, both transducers 641, 642 may simultaneously transmit and receivesignals. It is intended that any combination of using the transducers tosend and receive signals is contemplated. The device 632 also includes ahole-making assembly 638 for creating a channel in tissue. FIG. 5Eillustrates the hole-making assembly 638 as an RF wire-like member. Asillustrated, the device 632 is connected an RF generator 644 as well asan analyzing device 646 which is adapted to measure the Doppler shiftbetween the generated and reflected signals.

[0095]FIG. 5F illustrates the device 632 of FIG. 5E where thehole-making assembly 638 is retracted within the device 632, in thiscase within the elongated member 636.

[0096]FIG. 5G illustrates another variation of a device 648 where ahole-making assembly 650 is exterior to a transducer assembly 606. Thehole-making assembly 650 may be either an RF device or a mechanicaldevice that simply cuts the tissue. For example, the hole makingassembly 650 can be a hypotube placed over the transducer assembly 606.In this variation of the device 648, the transducer assembly 606 may bemoveable within the hole-making assembly 650, or the hole-makingassembly 650 may be moveable over the transducer assembly 606. In eithercase, the transducer assembly 606 may be advanced out of the hole-makingassembly 650 to determine the presence of a blood vessel. If no bloodvessel is found, the transducer assembly 606 may be withdrawn into thehole-making assembly 650 allowing the hole-making assembly 650 to createa channel in the tissue either by mechanically cutting the tissue, or byusing RF energy to create the channel. FIG. 5H illustrates a view takenalong the line 5H in FIG. 5G.

[0097]FIG. 5I illustrates another version of a device 652 of the presentinvention wherein the device has a transducer assembly 654 with anopening 658 through which a hole-making assembly 656 may extend. FIG. 5Jillustrates the hole-making assembly 656 extended through the transducerassembly 654. The hole-making assembly 656 may comprise RF electrodes orneedle-like members which puncture the tissue to create the channels.

[0098]FIG. 5K illustrates a variation of a device 666 of the presentinvention where a tip 660 of the device has a conductive portionallowing the tip to serve as both an acoustic lens and an RF electrode.In such a case, the tip 660 is connected to an RF generator 644 forcreating channels within tissue and a transducer 662 is placed incommunication with an analyzing device 646 that is adapted to measurethe Doppler shift between generated and reflected signals. In thisvariation, the tip 660 is separated from the transducer 662, but boththe tip 660 and transducer 662 are in acoustic communication through theuse of a separation medium 664. The separation medium 664 transmitssignals between the tip 660 and the transducer 662. The spacing of thetransducer 662 from the tip 660 serves to prevent heat or RF energy fromdamaging the transducer 662. It is intended that the spacing between thetransducer 662 and tip 662 shown in the figures is for illustrationpurposes only. Accordingly, the spacing may vary as needed. Theseparation medium must have acceptable ultrasound transmissionproperties and may also serve to provide additional thermal insulationas well. For example, an epoxy may be used for the separation medium.

[0099]FIG. 5L illustrates a variation of a device 680 of the presentinvention wherein the transducer assembly 670 comprises a tip 672, anultrasound coupling medium 674, a transducer 676, and an extensionmember 678. In this variation of the invention, the tip 672 of thedevice serves as an acoustic lens and also has conductive areas (notshown) which serve as RF electrodes. As shown in FIG. 5M, the tip 672may extend from the device 680 and separate from the transducer 676.Separation of the tip 672 protects the transducer 676 from heat or RFenergy as the tip 672 creates a channel in tissue. The extension member678 may serve as a conductor to connect the tip 672 to an RF energysupply (not shown). When the tip 672 of the device 680 is being used inan ultrasound mode, the tip 672 may be coupled to the transducer 676 viathe use of an ultrasound coupling medium 674. Any standard type ofultrasound gel material may be used, also highly formable silicone maybe used. It is desirable to use a fluid boundary layer (such as the gel)which may be permanent or temporary. In those cases where the boundarylayer is temporary, subsequent applications of the boundary layer may benecessary.

[0100]FIG. 5N illustrates another variation of a device 682 of thepresent invention having a tip 684 and transducer 686 that are separablefrom each other. Again, the tip 684 may include conductive areas andserve as both an RF electrode (not shown) as well as an acoustic lens.As shown in FIG. 5N, the tip 684 may be separable from the transducer686 when creating a channel to protect the transducer 686 from heat orRF energy. The tip 684 may be placed in contact with the transducer 686for operation in an ultrasound mode, or the device 682 may contain aseparation medium 688 which permits acoustic coupling of the transducer686 with the tip 684 when separated.

[0101]FIG. 5Q illustrates another variation of the inventive device 740which is able to detect the presence or absence of a blood vessel usingDoppler ultrasound and which is also able to create collateral channelswithin the lung tissue. The device includes a transducer adapted togenerate a source signal and receive a reflected signal with a portionof the assembly located adjacent to the distal end of the elongatemember 748. The transducer assembly may include at least one ultrasoundtransducer 742 and a lens 744 which enables the transmission anddetection of a signal over a tip of the device 740. The device 740further includes at least one heating element 746 located at a distalend of the lens 744. The heating element permits the device to createcollateral channels. In the variation depicted in FIG. 5Q, the heatingelement 746 comprises a plurality of openings 750 which allow forpassage of ultrasound signals through the heating element 746.Accordingly, the device 740 may use the transducer assembly to confirmthe absence of a blood vessel at a particular site, and then use theheating element to create a collateral channel. FIG. 5P illustrates afront view of the device 740 of FIG. 5P further illustrating the heatingelement 746 with a number of openings 750. The number of openings 750 ona heating element is not limited to that shown. Moreover, the heatingelement 746 may comprise a mesh having a plurality of openings.

[0102]FIG. 5R illustrates a variation of the inventive device whereinthe transducer assembly is moveable within a lumen of the elongatemember 748. As described elsewhere herein, the transducer assembly maybe moved when the heating element 746 is activated to create collateralchannels. FIG. 5R depicts the device 740 as being connected to a powersupply 752 and to an ultrasound controller device 754.

[0103]FIG. 5S illustrates another variation of a device of the presentinvention where the transducer assembly comprises at least onetransducer 608 and an acoustic lens 610 that is adapted to refract anddisperse a source signal over an outer surface of the lens 610. Asdescribed herein, the lens 610 is designed such that it interferes andredirects the signals in a desired direction. As illustrated, thetransducer assembly is coupled to an ultrasound controller device 754.The device 756 further includes a heating element 758 located distallyof the lens 610. The heating element 758 is coupled to a power supply752. Although the heating element 758 is illustrated as extending intothe elongate member 604 of the device 756, the device is not limited assuch. In one variation of the invention, the heating element 758 may beconfigured in a “U” shape. With this configuration, after the device 756penetrates tissue, rotation of the device 756 permits coring of thetissue to create a collateral channel. However, the heating element 758may be configured in other shapes as needed.

[0104]FIGS. 5T-5V illustrate another variation of the inventive device770 which is adapted to detect the presence or absence of a blood vesselusing Doppler ultrasound and which is also able to create collateralchannels within the lung tissue. In this variation, the device 770includes a detection device 600 adapted to determine the presence ofblood vessels, as discussed above, is moveably located within anelongate member 762. At least a portion of the lumen of the elongatemember 762 has a reduced opening 764 which is smaller than a diameter ofthe detection device 600. It is noted, that the detection device may beany detection device described herein.

[0105] As shown in FIG. 5V, a distal end of the elongate member 762 maybe radially adjustable to permit movement of the detection device 600 inand out of the lumen. In the variation of the device depicted in FIG.5V, a heating element 760 is placed on a distal end of the elongatemember 762. Accordingly, when the detection device 600 is advanced outof the elongate member 762, the detection device 600 may determine thepresence or absence of a blood vessel. Once a suitable location is foundfor the creation of a collateral channel, the detection device 600 isretracted into the elongate member 762, thereby positioning the heatingelement 760 to create a collateral channel. Optionally, as the heatingelement 760 generates heat as it creates the collateral channel, thedetection device 600 may be moved proximally to minimize the possibilityof any damage resulting from the generated heat. It should be noted thatthe elongate member may contain a shoulder to limit the depth of thecollateral channel. Alternatively, in another variation of theinvention, the detection device 600 may be configured to create acollateral channel via ultrasound energy. In such a case, no heatingelement is required and the expandable distal end of the elongate member762 may serve as a shoulder to limit the depth of the collateralchannel. In any case, as shown in FIG. 5U, when the device 770 isadvanced through the airways of a lung, the detection device 600 mayremain within the elongate member 762.

[0106] As with similar embodiments described herein, the distal end ofthe elongated member 762 may be remotely actuated to expand, or, thedistal end may be biased to expand outwardly. In the latter case, thedistal end may be restrained, for example, by an outer tubular member766. The outer tubular member 766 may also be used to reduce thediameter of the distal end to secure against the detection device 600,as shown in FIG. 5V. The distal end of the elongated member 762 may be acontinuous tubular structure which expands in diameter, or it may be atubular structure that divided into any number of portions 768 whichpermit radial expansion of the distal end. For example, FIG. 5Uillustrates a front view of the device of FIG. 5T in which at least asegment of the elongated member 762 is divided into four portions 768 sothat it may be radially adjustable. It is understood that the number ofportions 768 illustrated are merely exemplary, as the number may bevaried as needed. Furthermore, the elongated member 762 may not bedivided into any such portions 768 and instead may be an expandableelastic member.

[0107]FIGS. 6A-6F illustrate variations of RF electrode tip 690configurations for use with the present invention. As illustrated, theelectrodes may be placed around a circumference of a tip, longitudinalalong a tip, spirally along a tip, or a combination thereof. Theelectrodes 692, 694 may be used with a device having an acoustic lens orthe electrodes may be employed solely as an RF hole-making device. Whilethe variations illustrated in FIGS. 6A-6F show bipolar RF devices, theinvention may also use a single electrode (monopolar.) The tip 690 maycontain a first electrode 692 separated from a second electrode 694 byan electrical insulator 696 (e.g., ceramic, or plastic insulator). Invariations of the device where electrodes are positioned on an acousticlens, a sufficient amount of surface area of the lens must remainuncovered so that sufficient coupling remains for transmission of asignal between the lens and tissue. FIG. 6G illustrates a co-axialvariation of a bi-polar RF tip having a first electrode 692, a secondelectrode 694, and an insulator 696.

[0108]FIGS. 6H-6J illustrates additional variations of the lens of thepresent invention. FIG. 6H illustrates a device 724 with an acousticlens 726 having an oblate spheroid shape. FIG. 6I illustrates a device728 with an acoustic lens 730 having a prolate spheroid shape. FIG. 6Jillustrates a device 732 having a conical-shaped acoustic lens 734.These variations are only intended to illustrate variations of the lens.It is contemplated that the shape of a lens may not follow amathematical description such as conical, prolate, oblate orhemispherical. The design of the shape relates to the distributionpattern of the signal over the lens. The shapes can affect thedistribution pattern by making it wider or narrower as needed. In anycase, the lens is of a shape that provides coverage over the front faceof the device.

[0109]FIG. 7A illustrates a variation of the invention where a device700 includes a heat-sink member 702. The heat-sink member 702 maypreserve surround tissue during creation of the collateral channel. Or,the heat-sink member 702 may be a section of conductive material or aballoon. The heat-sink member 702 may be in fluid communication with alumen 704 that provides a fluid, such as saline, that conducts heat awayfrom the area surrounding the channel.

[0110]FIG. 7B illustrates another variation of a device 710 having afluid delivery assembly 706 which assists in preserving surroundingtissue while a channel is being created. The fluid delivery assembly 706may spray, mist, or otherwise apply fluid 708 to the area surroundingthe channel. For example, cooled saline may be applied to the area toprevent excessive heating of the target area.

[0111] The invention includes the use of hole-making assembly on theside of the device with a transducer assembly on the tip of the device.For example, FIG. 7C illustrates a variation of an RF electrode 712 foruse with the present invention. The electrode 712 may be a protrusionextending from a conductive member 716 that is covered with aninsulating material 714. In this variation, the electrode 716 limits thedepth of the channel due to the amount of material extending from theconductive member 716. The conductive member 716 may be connected to asource of RF energy (not shown) or may use another heating element (notshown). FIG. 7D illustrates another variation of an electrodeconfiguration. In this variation, the electrode comprises a sphericalmember 718 extending from an elongate member 722. The electrode 718 isretractable through the elongate member 722 by use of an actuator 720.The actuator 720 may be conductive and connected to a source of RFenergy to conduct energy through the electrode 718. Again, the design ofthe electrode 718 limits the depth of penetration of the electrode 718while creating a channel in tissue. The electrodes described herein mayalso be used in conjunction with a device having a Doppler arrangement.

[0112] Also, a variation of the invention contemplates the delivery ofdrugs or medicines to the area of the collateral opening. Alsocontemplated is the use of a fibrin, cyano-acrylate, or any otherbio-compatible adhesive to maintain the patency of the opening. Forexample, the adhesive could be deposited within the collateral channelto maintain patency of the channel or to create a cast implant of thechannel. The adhesive could also coat the channel, or glue a flap to thewall of the airway. Also, the use of a bioabsorbable material maypromote the growth of epithelium on the walls of the conduit. Forexample, covering the walls of a channel with small intestine submucosa,or other bioabsorbable material, may promote epithelium growth with thebioabsorbable material eventually being absorbed into the body.

[0113]FIG. 8A illustrates an implant or conduit 500 placed within anatural airway 100. As shown, the airway 100 has a portion of its wallremoved, thereby providing a collateral opening 112 within the airway100. The implant 500 typically has a porous structure which allowsgasses to pass between the airway and the channels 112 and into thelung. Moreover, the structure of the insert 500 also maintains patencyof the airway 100 and the channel 112.

[0114] Any variation of a conduit described herein may comprise abarrier layer which is impermeable to tissue. This aspect of theinvention prevents tissue in-growth from occluding the channel. Thebarrier layer may extend between the ends of the body or the barrierlayer may extend over a single portion or discrete portions of the bodyof the conduit.

[0115]FIG. 8B illustrates an conduit 500 having an expandable structurewithin an airway 100. Usually, the conduit 500 has a porous wall thatallows the passage of gasses through the wall. The conduit 500 isdelivered via a delivery device 502 which may also contain an expandablemember (not shown) which expands the conduit 500. As shown in FIG. 8C,the conduit may have piercing members 504 attached on an outer surfacewhich enable the conduit 500 to create an incision within the airway100.

[0116]FIG. 8C illustrates the conduit 500 after being expanded by anexpandable member 506, e.g. a balloon device, an expandable mechanicalbasket, or an expandable wedge. In this example, the conduit 500 expandsthrough the walls of the airway 100 at sections 508. In this variation,the conduit 500 is lodged within the walls of the airway 100.

[0117]FIG. 8D illustrates a grommet-like insert 503 where the lumen ofthe insert 503 extends longitudinally through the collateral channel. Inthis example, an expanding member 501, e.g., a balloon, an expandingmechanical basket, or the like is used to secure the conduit 503 withinthe collateral channel.

[0118] Although not illustrated, the invention includes conduits havinga length to diameter ratio approximately 1:1. However, this ratio may bevaried as required. The cross-section of an implant may be circular,oval, rectangular, elliptical, or any other multi-faceted or curvedshape as required. The cross-sectional area of an implant 500 may bebetween 0.196 mm² to 254 mm².

[0119] The conduit may also be any device capable of maintaining apatent opening, e.g., a plug, that is temporarily used as a conduit andthen removed after the channel has healed in an open position. Inanother variation the plug may be a solid plug without an opening thatis either bio-absorbable or removable. In such a case, the plug may beplaced within an opening in tissue and allow the tissue to heal forminga collateral channel with the plug being ultimately absorbed into thebody or removed from the body.

[0120] Another variation of the conduit is illustrated in FIG. 8E. Inthis example the conduit 510 comprises a cone 514 with a grommet 512 forattachment to a wall of the airway 100. The cone 514 may be porous orhave other openings 516 to facilitate the passage of gas through thecollateral channel. In the event that the distal opening of the conebecome occluded, the porous cone permits the continued exchange ofgasses between the collateral channel and the natural airway.

[0121] Another variation of the conduit is illustrated in FIG. 8F. Forexample, the conduit 518 may be configured in a ‘t-shape’ with a portion520 of the conduit extending through the collateral channel. Again, theconduit 518 may be constructed to have a porous wall to allow gasexchange through the wall. The conduit may be configured in a variety ofshapes so long as a portion of the conduit extends through thecollateral channel. The portion may be formed into a particular shape,such as the ‘t-shape’ described above, or, the portion may be hinged sothat it may be deployed within the channel. In such a case, a portion ofa wall of the conduit may have a hinge allowing the wall of the conduitto swivel into a channel.

[0122] Yet another variation of the conduit is found in FIG. 8G. In thisexample, the conduit 522 is constructed with a geometry that reduces thechance that the conduit 522 will migrate within the airway 100.

[0123]FIG. 8H illustrates an example of a conduit 524 having anasymmetrical profile. The conduit 524 may have a flange 526 at either orboth ends of the body 528. Although not shown, the flange 526 may have acone-like profile to facilitate placement within an airway. Asillustrated in FIG. 8I, the asymmetrical profile of the conduit 524assists in preventing obstruction of the airway.

[0124]FIG. 8J illustrate a variation of the conduit 530 having aself-cleaning mechanism. In this example, the self cleaning mechanism isa floating ball bearing 532. The ends of the conduit 530 have a reduceddiameter 534 which prevents the bearing 532 from escaping. As gas passesthrough the conduit 530, the bearing 532 moves about the conduit 530clearing it of debris. The shape of the bearing 532 and the size andshape of the reduced diameter 534 may be varied to optimize theself-cleaning effect of the device.

[0125]FIGS. 8K and 8L illustrate another variations of a self-expandingconduit 536. In this example, as shown in FIG. 8K, the conduit 536 maybe constructed from a flat material 538 having a spring or springs 540.As shown in FIG. 8L, the conduit 536 is formed by rolling the assembly.The spring 540 provides an expanding force against the material 538. Theconduit 536 may also be constructed so that the flat material 538 isresilient thus eliminating the need for springs 540.

[0126]FIG. 8M illustrates another variation of an expandable conduit 542constructed from a braided material. The conduit 542 may be constructedso that the diameter is dependent upon the length of the device 542. Forexample, the diameter of the device 542 may decrease as the length isstretched, and the diameter may increase as the length of the device 542is compressed. Such a construction being similar to a ‘finger cuff’ toy.

[0127]FIGS. 8N-8P illustrate another variation of a grommet-typeconduit. FIG. 8N illustrates a conduit 544 having expandable ends 546.In one variation the ends 546 of the device 544 may flare outwards asillustrated in FIG. 5P. FIG. 8N illustrates another variation of thedevice 544 in which the ends 546 compress in length to expand indiameter.

[0128]FIGS. 8Q and 8R illustrate variations of a conduit having ananchor. In FIG. 8Q, the conduit 548 has an anchor 550 at a distal end ofa hollow plug 540. The anchor 550 may be tapered to facilitate entryinto the airway 100 wall or may have another design as required. Theanchor 550 also contains ventilation openings 552 to facilitate gasexchange through the device. FIG. 8R illustrates another variation ofthe device.

[0129]FIG. 8S illustrates a variation of a conduit 561 having flanges563 at either end to assist in placement of the conduit within an airwaywall (not shown). The ends of the conduit 565 may be tapered to easeplacement through a collateral channel. The conduit has an opening 565to facilitate passage of air. To simplify construction, the conduit 561may be constructed from a biocompatible material, such as stainlesssteel, or plastic.

[0130]FIG. 8T illustrates a variation of the invention having multipleopenings for gas flow. The conduit 560 has a first hollow end 564 whichcan extend through a wall of the airway 100 and a second hollow end 566which can remain parallel to the airway 100. This example also includesan opening 562 which allows gas to flow through the airway 100.

[0131]FIG. 8U illustrates a variation of the device having a one-wayvalve 570. The valve 570 allows the conduit 568 to permit exhaust of theair sac but prevents the conduit 568 from serving as another entrance ofgas to the air-sac. The valve 570 may be placed at ends of the conduitor within a lumen of the conduit. The valve 570 may also be used asbacterial in-flow protection for the lungs.

[0132]FIG. 8V illustrates another variation of a conduit 572. In thisvariation, the conduit 572 may be a sponge material, or constructed ofan open cell material 574, which allows air flow through the material.Or, the conduit 572 may have lumens 576 which allow flow through theconduit 572. To assist the conduit 572 in remaining within a channel,the conduit material may be selected such that it expands as it absorbsmoisture. Also, the sponge material/open cell material may bebio-absorbable to allow for temporary placement of the conduit 572.

[0133]FIGS. 9A-9F illustrate another variation of a conduit 800 of thepresent invention. The conduit 800 has a center section 802 havingextension members 804 located at either end of the center section 802.The center section 802 illustrated is tubular but may be of any othershape as needed for the particular application. The conduit of theinvention has a passageway extending between the ends of the conduitsuited for the passage of air. The variation of the conduit 800illustrated in FIG. 9A has a center section 802 comprising a mesh formedfrom a plurality of ribs 806. FIGS. 9A and 9B illustrate the conduit 800in a reduced profile while FIGS. 9C and 9D illustrate the conduit 800 inan expanded profile after expansion of the center section 802 of theconduit 800. As shown in FIGS. 9E and 9F, each free end 808 of eachextension member 804 is unattached to the center section 802 and isbendable about the respective end of the center section 802 to which itis attached. Accordingly, once a conduit 800 is placed within acollateral channel (not shown), the extension members 804 are bent aboutthe end of the center section 802 and form a cuff or grommet whichassists in keeping the conduit 800 within a collateral channel.Accordingly, the cross section and number of extension members 804located about either end of the conduit 800 may be selected as necessaryto assist in placement and securing of the conduit 800 within a channel.

[0134] The conduits described herein may have a fluid-tight covering, asdiscussed below, about the center section, the extension members, or theentire conduit. Also, the conduit may be designed to limit a length ofthe center section to less than twice the square root of a crosssectional area of the center section when the center section is in theexpanded profile.

[0135]FIGS. 9G-9I illustrates another variation of a conduit 812 for usewith the invention. In this variation, the conduit 812 is formed from arolled sheet of material 810. The rolled sheet 810 may be heat treatedto preserve the shape of the conduit 812 or the sheet 810 may simply berolled to form the conduit 812. In those cases where the sheet ofmaterial 810 comprises a shape-memory alloy, it is desirable to processthe material 810 so that it exhibits super-elastic properties at orabove body temperature.

[0136]FIG. 9G illustrates a variation of extension members 820 for usewith a conduit (not shown) of the present invention. In this variation,the extension members 820 have an attachment 822 between adjacentextension members 820. FIG. 9H illustrates the extension members 820 asthe conduit (not shown) is expanded and the extension members 820 arebent on the conduit. The attachment 822 assists in preventing theextension members 820 from deviating from a preferred position. Asillustrated in FIG. 9I, the conduit 826 may have cut or weakenedsections 824 to facilitate expansion of the conduit 826 and bending ofthe extension members in a desired manner (as shown by the section of828).

[0137]FIGS. 9J-9K illustrate various additional cross sectional designsof conduits. FIG. 9J illustrates a possible conduit design 830 havingextension members 834 attached to a center section 832. FIGS. 9K and 9Lillustrate additional variations of conduit designs. As illustrated inFIGS. 9K and 9L, the extension members 840, 846 and center sections 838,844 are designed to form a diamond pattern upon expansion of theconduit. FIG. 9K further illustrates a variation of an extension member840 having an opening 841 to facilitate tissue in-growth and therebysecures placement of the conduit. FIG. 9M illustrates an expandedconduit 848 having the diamond pattern referred to above. The conduit848 also contains a fluid-tight barrier 851 on the center section 850 ofthe conduit 848. Although not illustrated, fluid-tight barrier may beplaced throughout a conduit. Another feature of the variation of FIG. 9Mis that the extension members have a diamond pattern construction, thisconstruction assists in maintaining alignment of the extension membersallowing for a preferred aligned expansion of the extension members.

[0138]FIGS. 9N-9O illustrate another variation of a conduit 860 of thepresent invention. In this variation, the conduit design 854 may haveextension members 856 at only one end of the conduit 860. In thisvariation, the center section of the conduit may comprise a body portion858. The conduit 860 may have a covering about a portion of the conduit860. The covering may extend throughout the length of the conduit 860 orit may be limited to a portion of the conduit 860. As illustrated inFIG. 9O, when expanded, the conduit 860 may form a reduced area 858 nearthe extension members 856. As mentioned above, the conduit cross section854 may be designed such that the a diamond pattern is formed uponexpansion of the conduit 860, as illustrated in FIG. 9O.

[0139]FIG. 9P illustrates a sheet of material 810 having extensionmembers 814 extending from either end of the sheet 810. Although thesheet 810 is illustrated to be solid, a conduit may be formed from asheet having openings within the center section of the sheet. FIG. 9Qillustrates the conduit 812 where the rolled sheet 810 comprises acenter section 818 of the conduit 812 and the extension members 814 fromeither end of the center section 818. As illustrated in FIG. 9Q, thesheet 810 may be overlapped for a reduced profile and expanded into anexpanded profile. FIG. 9R illustrates a free end 816 of each extensionmember 814 as having been bent away from a central axis of the conduit812. As with any variation of a conduit of the present invention, theextension members 814 of the conduit 812 may be bent away from a centralaxis of the conduit 812 up to 180° with respect to the central axis. Asmentioned above, the cross section and number of extension members 814located about either end of the conduit 810 may be selected as necessaryto assist in placement and securing of the conduit 810 within a channel.

[0140] In those cases where the conduit 812 of FIG. 9Q comprises anon-shape memory alloy the conduit 812 will be actively mechanicallyexpanded. In those cases where the conduit 812 is comprised of a shapememory alloy, such as a super-elastic alloy, the conduit 812 may bepre-formed to assume a deployed shape which includes a grommet formed byextension members 814 and an expanded center section 818, such as theshape illustrated in FIG. 9R. Next, the super-elastic conduit 812 may berestrained or even rolled into the shape illustrated in FIG. 9Q. Becausethe conduit 812 is formed of a super-elastic material, no plasticdeformation occurs. When the super-elastic conduit 812 is then placedwithin a collateral channel, the conduit 812 may naturally resume itspreformed, deployed shape.

[0141]FIG. 9S illustrates another variation of a conduit 862 having afirst portion 864 and a second portion 866 and a passageway 868extending therethrough. The first portion 864 may be a conduit design asdescribed herein. In particular, the first portion 864 is configured tosecure the conduit 862 to the airway wall 100. Accordingly, the firstportion 864 may or may not have a center that is expandable. The wallsof the first portion 864 may be fluid-tight (either through design, or afluid tight covering) to prevent tissue in-growth through the collateralchannel. Alternatively, the first portion 864 may be partiallyfluid-tight to facilitate tissue in-growth to improve retention of theconduit 862 to the airway wall 100. However, in the latter case, thefirst portion 864 should be designed to minimize tissue in-growth withinthe channel to prevent substantial interference with airflow through theconduit 864. As with the first portion 864, the walls of the secondportion 866 of the conduit may or may not be fluid-tight. If the secondportion 866 is not fluid-tight, the larger area provides for improvedairflow from lung tissue through the passageway 868 and into the airway.The second portion 866 may also be designed to be partially fluid-tightto encourage airflow through the conduit 862 but reduce the probabilityof blockage of the conduit 862.

[0142]FIGS. 9T-9U illustrate another variation of a conduit 870. Forexample, the conduit 870 may be formed from a tube that is slit to formextension members at a first portion 872 and second portion 876 with acenter section 874 between the portions. The conduit 870 may be expandedas shown in FIG. 9U such that the first 872 and second 876 portionsmaintain the center portion 874 in a collateral channel in an airwaywall. The center section 874 may or may not be expandable.

[0143]FIG. 9U illustrates the second portion 876 of the conduit 870 toexpand in its center, however, the conduit 870 may be designed in otherconfiguration as well (e.g., expanded to have a larger diameter at anend opposite to the center section 874.) However, a central aspect ofthis design is that the second portion 870 provides a large area in thelung tissue to permit a larger volume of air to pass from the lungtissue into the conduit 870. This design has an added benefit as thesecond portion 876 cannot be easily blocked by flaps of parenchymatissue. A simple variation of the conduit 870 may be constructed from ametal tube, such as 316 stainless steel, titanium, titanium alloy,nitinol, etc. Alternatively, the conduit may be formed from a rigid orelastomeric material.

[0144] The conduits described herein may be comprised of a metallicmaterial (e.g., stainless steel), a shape memory alloy, a super-elasticalloy (e.g., a NiTi alloy), a shape memory polymer, a polymeric materialor a combination thereof. The conduit may be designed such that itsnatural state is an expanded state and it is restrained into a reducedprofile, or, the conduit may be expanded into its expanded state by avariety of devices (e.g., a balloon catheter.) The conduit describedherein may be manufactured by a variety of manufacturing processesincluding but not limited to laser cutting, chemical etching, punching,stamping, etc.

[0145] The conduits described herein may be coated with an elastomer,e.g., silicone, polyurethane, etc. The coatings may be applied, forexample, by either dip coating, molding, or liquid injection molding(for silicone). Or, the coating may be a tube of a material and the tubeis placed either over and/or within the conduit. The coating(s) may thenbe bonded, crimp, heated, melted, or shrink fit. The coatings may alsobe placed on the conduit by either solvent swelling applications or byan extrusion process. Also, a coating of may be applied by eitherwrapping a sheet of PTFE about and/or within the conduit, or by placinga tube about and/or within the conduit and securing the tubes.

[0146] Another variation of the invention is illustrated in FIGS.10A-10B. In this variation, a conduit of the present invention containsa filler material between the openings of the ribs or mesh. For example,FIG. 10A illustrates a partial plane view of a conduit 880 having aplurality of ribs or a mesh structure 882 as previously described. Theconduit 880 includes placing a filler material 884 between each of theribs/opening of the mesh. A covering 886 is then placed over theribs/mesh 882 and filler material 884. The covering 880 encapsulates thestructure of the conduit 880 and covers the outer surface of the conduit880 and the interior wall of the lumen or passageway of the conduit 880.FIG. 10B illustrates a partial sectional view of the conduit 880 of FIG.10A. FIG. 10B illustrates the mesh 882 with filler material 884 adjacentto the mesh 882 and an outer covering 886 encapsulating the mesh 882 andfiller material 884. It is noted that the filler material 884 andcovering 886 may be placed entirely throughout a conduit. Alternatively,the filler material 884 and covering 886 may be placed partially over aconduit as needed. It is believed that the addition of filler materialto a conduit of the present invention provides a uniform thickness ofthe covering which results in uniform and consistent stretching of thecovering. Some various examples of filler material are, for example,wax, silicone, and urethane. The covering may consist of, for example,silicone, urethane, or similar materials. FIGS. 11A-11C illustrateanother variation of a conduit 888 of the present invention. In thisvariation, the conduit comprises a continuous phase material 896 that isweak enough to expand but strong enough to keep a particular size andshape upon expansion of the conduit 888. Some examples of a continuousphase material are polytetrafluoroethylene and polypropylene. Thesematerials exhibit plastic deformation without exhibiting tears orbreaches in their surfaces when expanded. These materials may beselected to have a properties (e.g., modulus, yield stress, etc.) whichpermit expansion of the conduit into a desired shape and retention ofthat shape. To further assist in controlling the expansion and shape ofthe installed conduit 888, the conduit may have weakened sections thatpermit the ends of the conduit to bend as desired. For example, the wallthickness of the conduit 888 may vary as illustrated. As shown in FIG.11A, the wall thickness of the material 896 between the extensionmembers 890 and the center section 892 may be less than a thickness ofthe wall section of the material 896 at the center section 892. Asillustrated, if an outwardly radial force is applied to the extensionmembers 890, such a configuration results in a higher bending stress atthe area of reduced wall thickness 894. As a result, and as illustratedin FIGS. 11B-11C, the extension members 890 expand in a predeterminedmanner.

[0147] As mentioned above, the number of and cross sectional area of theextension members on a conduit may be selected as needed for theparticular application. Also, the extension members may be bent suchthat they anchor into the tissue thereby securing placement of theconduit. Or, the extension members or the center section may containbarbs or other similar configurations to better adhere to the tissue.Moreover, the orientation of the extension members may vary as well. Forexample, the extension members may be configured to be radiallyexpanding from the center section, or they may be angled with respect toa central axis of the conduit. Another variation of the inventionincludes a radioactive conduit which inhibits or prevents the growth oftissue within the conduit.

[0148] Although the conduits of the current invention have beendescribed to contain expandable center sections, the invention is notnecessarily limited as such. Instead, the design of the conduit mayrequire extension members on the ends of a conduit with a non-expandablecenter section.

[0149]FIGS. 12A-12D illustrate a conduit 900 of the present invention.The deployment of the conduit 900 is intended to show an example of apossible means of deployment only. Accordingly, the inventive conduitmay be delivered at an angle via an articulating or jointed device, theconduit may be delivered on a device that is adapted to locate andcreate the collateral channel, or the conduit may be delivered on adevice having other features as needed for the particular application.

[0150]FIG. 12A illustrates the conduit 900 being delivered to acollateral channel in an airway wall 114 via a delivery device (e.g., aballoon catheter 902.) The conduit 900 may be attached to the deliverydevice 902 using the natural resiliency of the conduit 900. Or, in thosecases where the conduit is spring loaded, the conduit 900 restrained ina reduced profile and may be removably affixed to the delivery device902 using an adhesive, or a removable sleeve such as a heat shrink tube.In this example, the balloon catheter 902 has several balloons includinga distal balloon 904, a proximal balloon 906, and a center balloon (notillustrated in FIG. 12A). FIG. 12B illustrates the inflation of thedistal 904 and proximal 906 balloons to situate the extension members908. Accordingly, the extension members 908 for a flange or collet aboutthe airway wall 114. The balloons 904, 906 may be inflatedsimultaneously, or in a desired sequence. In any case, deployment of theballoons 904, 906 may serve to center the conduit 900 in the collateralchannel.

[0151]FIG. 12C illustrates inflation of the center balloon 912 whichcauses expansion of the center section 910 of the conduit 900. If theconduit 900 is affixed to the delivery device 902, expansion of thecenter balloon 912 causes release of the conduit 900 by release of theadhesive or breaking of the heat shrink tubing (not shown). In any case,the means of attachment may be bioabsorbable and remain in the body, ormay remain affixed to the delivery device 902 and is removed withremoval of the delivery device 902. FIG. 12D illustrates the conduit 900affixed to the airway wall 114 after the delivery device 902 is removedfrom the site. Another method of deploying a conduit includesrestraining the conduit about a delivery device using a wire or stringtied in a slip-knot or a series of slip-knots. When the conduit isdelivered to a desired location, the proximal end of the wire or stringmay be pulled which releases the wire/string and deploys the conduit.FIGS. 12E and 12F illustrate possible ways to manipulate a conduit 914for placement in an airway wall 114 using a delivery device 916. FIG.12E illustrates deployment of a delivery device 916 to place a conduit914 within an opening in an airway wall 114. The conduit 914 may beplaced over a balloon 918 (or other expandable section) of the deliverydevice 916. FIG. 12F illustrates deployment of the balloon 918 to placeand expand the conduit 914. In the variation illustrated in FIGS. 12Eand 12F, a balloon 918 serves several functions. The balloon 918 firstexpands and starts bending the extension members 920. The balloon 918continues to center the conduit 914 on the tissue and simultaneouslybegins to expand the conduit 914 and secures the conduit to the tissue.

[0152]FIGS. 12G and 12H illustrate additional variations of deploymentdevices. In these variations, the deployment devices 922, 926 containhourglass-shaped balloons 924, 928. The hour glass-shaped balloons 924,928 contain an interior profile 923. For deployment of a conduit (notshown) of the present invention, the conduit is placed on the balloon924, 928. As the balloon 924, 928 expands, the conduit expansion matchesthe interior profile 923 of the balloon 924, 928. Accordingly, the hourglass-shaped balloon 924, 928 may be used to set the angle andorientation of the expandable members of a conduit as well as theexpansion of a center section of the conduit.

[0153]FIG. 12I illustrates another variation of an hour glass shapedballoon delivery device 930. This variation of the hour glass shapedballoon 932 is designed to expand extension members (not shown) of aconduit (not shown) at a particular angle 934. The orientation of theballoon 932 may be designed as needed to impart the desired angle to theextension members of the conduit. The balloons described herein may beconstructed of polyethylene terephthalate (PET) or any other materialwhich is used in the construction of balloon catheters.

[0154]FIG. 13A illustrates a method of placing a conduit within lungtissue. FIG. 13A illustrates the advancement of an access device 940into the airways 100 of a lung. The access device 940 will have at leastone lumen or working channel 942. The access device 940 will locate anapproximate site 944 for creation of a collateral channel. Abronchoscope or other similar type of endoscope may be used as theaccess device 940. In cases where the access device 940 is abronchoscope or similar device, the access device 940 is equipped sothat the surgeon may observe the site for creation of the collateralchannel. However, it is contemplated that the method of placing aconduit within lung tissue may be performed using non-invasive imagingtechniques as well. In such a case, the access device 940 as well as theother devices discussed herein, may be configured for detection by theparticular non-invasive imaging technique such as fluoroscopy,“real-time” computed tomography scanning, or other technique being used.

[0155]FIG. 13B illustrates a blood vessel detection device 946 advancedthrough the channel 942 of the access device 940 towards the site 944.The site 944 is then inspected to determine whether a blood vessel isadjacent to the site. As discussed herein, it may be desirable to avoidblood vessels when creating a collateral channel. Some possible examplesof the detection device 946 are disclosed throughout this disclosure.

[0156]FIG. 13C illustrates the creation of a collateral channel 112 by ahole-making device 948. Examples of hole-making devices 948 aredisclosed throughout this specification. Furthermore, variations of thisinvention include the use of devices which are equipped for detectionand hole-making. Such devices are also disclosed throughout thisspecification. As shown in FIG. 13C, the device 948 may be manipulatedto a position that is optimal for creation of the collateral channel112. It is noted that the access device or the hole-making device may besteerable. Such a feature may assist in the positioning of any of thedevices used in the inventive method. Although it is not illustrated, asdiscussed herein, it is desirable to create the collateral channel suchthat it is in fluid communication with an air-sac. The fluidcommunication allows for the release of trapped gasses from thehyper-inflated lung.

[0157]FIG. 13D illustrates another variation of the inventive method inwhich a guide-member, such as a guide-wire 950, or other similar device,is inserted into the collateral channel 112. It is noted that the use ofa guide-member 950 is optional.

[0158]FIG. 13E illustrates the advancement of a catheter device 952 intothe collateral channel. In the variations using a guide-member 950, thecatheter 952 is advanced over the guide-member 950 and into thecollateral channel 112. One variation of the inventive method includesthe use of a catheter 952 which has a conduit 954 attached thereto. Someexamples of the conduit 954 as well as catheter type delivery devices952 are disclosed throughout this disclosure. If the conduit 954 is ofthe type that is not self-expanding, the catheter 952 may also beconfigured to expand the conduit 954 within the collateral channel 112.

[0159]FIG. 13F illustrates the conduit 954 placed within the collateralchannel 112 and the withdrawal of the guide-member 950, catheter 952,and the access device 940. As shown by the arrows of FIG. 13F, theconduit 954 maintains the collateral channel 112 open so that trappednon-functional air is evacuated from the hyper-inflated lung.

[0160] It is noted that a variation of the inventive method includesusing a guide-wire to create the collateral channel and leaving theguide-wire to extend through the collateral channel. Accordingly, aconduit may be advanced over the guide-wire into the collateral channel.

[0161] The invention further includes methods of evaluating individualshaving a diseased lung to assess inclusion of the individual for theprocedure.

[0162] The method comprises the steps of performing pulmonary functiontests on the individual. The pulmonary function tests may obtain suchvalues as FEV (forced expiratory volume), FVC (forced vital capacity),FEF_(25%-75%) (forced expiratory flow rate), PEFR (peak expiratory flowrate), FRC (functional residual capacity), RV (residual volume), TLC(total lung capacity), and/or flow/volume loops.

[0163] FEV measures the volume of air exhaled over a pre-determinedperiod of time by a forced expiration immediately after a fullinspiration. FVC measures the total volume of air exhaled immediatelyafter a full inspiration. FEF_(25%-) _(75%) measures the rate of airflow during a forced expiration divided by the time in seconds for themiddle half of expired volume. PEFR measures the maximum flow rateduring a forced exhale starting from full inspiration. FRC is the volumeof air remaining in the lungs after a full expiration. RV is the FRCminus the expiratory reserve volume. TLC is the total volume in thelungs at the end of a full inspiration. Flow/volume loops are graphicalpresentations of the percent of total volume expired (on the independentaxis) versus the flow rate during a forced expiratory maneuver.

[0164] The invention further comprises methods to determine thecompletion of the procedure. This variation of the invention comprisesthe step of performing pulmonary function tests as described above,creating collateral channels in the lungs, performing a post-procedurepulmonary function test, obtaining clinical information, comparing theresults of the tests, evaluating the clinical information with theresults of the test to determine the effectiveness of the procedure.

[0165] Another method to determine the completion of the procedureincludes checking the resistance of airflow upstream from a location ofa collateral channel. The method includes making a collateral channel,checking airflow, measuring resistance to airflow, and repeating theprocedure until acceptable resistance is obtained. Because thecollateral channel allows for the release of trapped air, the resistanceto airflow should decrease. A body plethysmograph or other suitableequipment used to measure in pulmonary medicine may be used to determinethe resistance to airflow.

[0166] A measurement of total lung volume may be used to determine whenthe lung is suitably deflated and therefore when enough collateralchannels are created. Or, non-invasive imaging may be used to determinepre and post procedure lung volume or diaphragm position.

[0167] An evaluation of the effectiveness of the procedure may alsoinclude creating a collateral channel then sealing the channel with aballoon catheter. The distal end of catheter is then opened for ameasurement of the flow of trapped air through the catheter.

[0168] This variation of the invention includes obtaining clinicalinformation regarding the quality of life of the individual before andafter any procedures, physical testing of the pulmonary system of theindividual, and a general screening for pulmonary condition.

[0169] The invention further includes a medical kit for improvinggaseous flow within a diseased lung. The components of the kit mayinclude a conduit, a hole-making device, and/or a detection device allof which are of the present invention and as described herein. The kitmay further contain a power supply, such as an RF generator, or aDoppler controller which generates and analyzes the signals used in thedetection devices. The kit may include these components either singly orin combination. The kit of the present invention may also containinstructions teaching the use of any device of the present invention, orteaching any of the methods of the present invention described herein.The instructions may actually be physically provided in the kit, or itmay be on the covering, e.g., lidstock, of the kit. Furthermore, the kitmay also comprise a bronchoscope, or guide-member (such as aguide-wire), or other such device facilitating performance of any of theinventive procedures described herein.

[0170] The invention herein is described by examples and a desired wayof practicing the invention is described. However, the invention asclaimed herein is not limited to that specific description in anymanner. Equivalence to the description as hereinafter claimed isconsidered to be within the scope of protection of this patent.

1. A method of placing a conduit within lung tissue comprising: feedinga guide-wire to a site within the lung; advancing a conduit to the siteusing the guide-wire; and placing the conduit within lung tissue at thesite.
 2. The method of claim 1, further comprising inserting an accessdevice within the lung, the access device adapted to locate the siteprior to the feeding step, wherein the access device includes at leastone lumen.
 3. The method of claim 2, wherein the access device comprisesa bronchoscope.
 4. The method of claim 2, further comprising: feeding ablood-vessel detection device through the lumen of the access device;and selecting the site within the lungs using the blood-vessel detectiondevice to avoid blood vessels within the lung.
 5. The method of claim 2,further comprising: feeding a guide-wire through the lumen of the accessdevice; and creating a collateral channel with the guide-wire at thesite prior to placing the conduit.
 6. The method of claim 5, furthercomprising: leaving the guide-wire extending through the collateralchannel and withdrawing the access device from the lung
 7. The method ofclaim 6, further comprising: returning the access device to a point nearthe collateral channel to allow visualization of the collateral channel8. The method of claim 2, further comprising: feeding a hole-makingdevice through the lumen of the access device; and creating a collateralchannel with the hole-making device at the site prior to placing theconduit.
 9. The method of claim 8, wherein feeding the guide-wire to thesite comprises feeding the guide-wire through the collateral channel.10. The method of claim 2, wherein advancing the conduit comprisesfeeding a catheter having a conduit attached thereto over the guide-wireto the collateral channel.
 11. The method of 10, wherein placing theconduit within lung tissue further includes expanding the conduit withinthe collateral channel. 12-37. (canceled)
 38. The method of claim 1,further compromising visualizing the placement of the conduit usingradiological imaging.
 39. The method of claim 38, further compromisingvarious agents are used to enhance the visibility of hyperinflatedportions of the lung.
 40. The method of claim 2, further comprisingcreating a collateral channel at the site and feeding a balloon devicethrough the access device to dilate the collateral channel.
 41. Themethod of claim 2, further compromising feeding a drug delivery devicethrough the access device; and to the formed collateral channel.
 42. Themethod of claim 41, further compromising drugs or medicines aredelivered through the device.
 43. The method of claim 41, furthercompromising bio-compatible adhesives are delivered through the device.44. The method of claim 1, further compromising determination ofcollateral ventilation used to aid in creating a collateral channel atthe site.